M/s PCLSite Location:
Indian Railways had taken up the arduous task of linking the Kashmir Valley with Jammu by a rail network of 343 km. The work on first phase (56 Kms) between Jammu to Udhampur was completed in 2005 and services are operational on this route. The link 25 Km between Udhampur to Katra Vaishnodevi is under construction and may be completed by 2007. The work on 119 km track from Qazigund to Baramulla is nearing completion. The 138 km stretch between Katra to Qazigund was commenced in 2003. However this stretch is one of the most difficult and un-parallel to any rail linking project built in India so far. It involves 104 kms of tunneling wherein one tunnel is about 10.9 km long under a rock cover of 2000 mts below the Pirpanjal range of Himalayas.
This herculean task of 138 km has been entrusted to two public sector companies; from Katra to Laole between Km 30 to Km 120 to Konkan Railway Corporation Ltd (KRCL) and from Laole to Qazigund between Km 120 to 168 to IRCON International.
In Konkan Railway section, to execute entire 90km track length, construction of 225 km access road is necessary which has become a bottleneck to complete this project on time. Roads are to be built first and the railway tunnels later. The sector has a complicated topography consisting of deep gorges & heavy sliding zones.
The entire Railway Track meanders through young Himalayan Mountains which consist of sinking / slide zones. One such tough zone has been noticed at Tunnel No 1 at Katra (J&K), where the portal got buried under the slush & muck during the construction of the tunnel. This tunnel was being constructed by M/ s Progressive Constructions Ltd.
Following the slide, the work was suspended for sometime; further discussion and proposals were undertaken with various consultants and agencies to avoid such unfortunate incidences in future.
Finally, the exisiting muck was cleared and a false tunnel 30.0 m in length was constructed from the face of the tunnel. The Portal of the Tunnel consists of more than 100 m high slide zone, which is very vulnerable to land slides during the rains. In order to protect the false tunnel, after closure of the tunnel from the slide and washing away of the foundation soil from both side of the portal, it was proposed to have Reinforced Soil Walls on both the sides of the tunnel.
The proposed Reinforced Soil Wall would act as impact resistance pad on both sides of the tunnel taking the load of the slush / muck which may come over the tunnel with high momentum endangering the foundation of the portal.
M/s PCL contacted TechFab India, who is an ISO 9001: 2000 certified and one of the leading manufacturers of geosynthetics & the only manufacturer of CE Mark certified knitted & PVC coated PET geogrids in the country.
TechFab India has considerable experience & expertise in the design and execution of reinforced soil structures, supply of geogrids & accessories, and supervision during the construction of reinforced soil walls. TechFab India prepared & submit the design & drawings of reinforced soil walls, based on BS 8006 for static loading & on FHWA for seismic zone IV loading. The design of reinforced soil wall was duly checked by KRCL’s consultant and was dully proof checked by IIT, Delhi. TechFab India have supplied all the required quantity of geogrids & accessories and M/s PCL is presently erecting the reinforced soil walls under the supervision of TechFab India’s experts.
The reinforced soil wall is 10.0 m high on either side with Wire Mesh Fascia with wrap-around technique. Once complete, the RE Wall shall be vegetated with locally suited plants to give it a natural look and provide additional stability against erosion.
The typical cross section of reinforced soil wall is shown below.
TechFab India Industries Ltd.
711/712, Embassy Centre,
Nariman Point, Mumbai – 400021
022- 2287 6218